The present invention relates to a rotatable seat for an automotive vehicle, such as van or micro-bus and so forth. More specifically, the invention relates to a rotating mechanism and locking or latch mechanism in the rotatable seat.
Recently, rotatable seats for use on the automotive vehicles, particularly on van or micro-bus type vehicles, have been developed. Generally, such rotatable seats are provided with a rotation or pivot mechanism and a latch mechanism. The rotation mechanism comprises a vertical axle rotatably received within a boss formed on the vehicle floor panel. The latch mechanism is usually provided adjacent the rotation mechanism and prevents the vertical axle from rotating. The latch mechanism has a latch member engageable with the vertical axle or other appropriate section of the rotation mechanism so that it may prevent the vertical axle and thus the rotatable seat from rotating.
Since the rotational force due to inertia caused by collision of the vehicle or abrupt deceleration is applied to the vehicle not only at the pivoted portion but also at locations spaced from the pivot, the conventional latch mechanism must provide enough force to prevent the seat from rotating. However, due to a lack of space below the seat, there could not be provided an appropriate mechanism having enough resistance against the rotational force applied to the portion apart from the pivot. Furthermore, according to the typical construction of the conventional rotatable seat, the latch member is urged into its latching position by a spring. This bias spring provided for the latch member has insufficient bias force for completely preventing the seat from accidentally rotating. On the other hand, between the bottom of the seat and the vehicle floor panel there is not enough clearance for a spring powerful enough to bias the latch member to the latching position. Assuming it is possible to provide a spring having enough force to prevent the seat from accidentally rotating, this may cause difficulty in releasing the seat from the latching position when the seat is to be rotated.
Preventing the seat from accidentally rotating may be accomplished by providing a latch mechanism at a position spaced from the pivot, where greater rotational force with respect to the pivot will be applied. This may require less biasing force than the latch mechanism provided adjacent the pivot. Therefore, releasing of the latch mechanism from the latching position may require less power to permit easy operation of seat rotation when the seat is to be rotated.